Cartridge



L. P. BOLL CARTRIDGE June 10, 1930.

Filed April 14, 1927 M FM Patented June 10, 1930 i UNITED [STA TasV PATENT ori-lcs p LESTER P. 301.150!l MAPLEWOOD, MISSOURI, ASSIGN'OIR. T0 W. N. MATTHEWS CORPO- f BATION, OFBT. LOUIS, MISSOURI, A. CORPORATION F MISSOURI CARTRIDGE Application med April 14,

This invention relates to fuses and with regard to.,ecertainmore specific features, to fuse cartridges. The general type of switch box involved is shown in prior Patents, No.

1,288 951, and No. 1,398,335, issued to Claude L1 Matthews and Walter A. Heinrich, December 24, 1918, and November 29, 1921, re-

spectively. y

The general type of useswitch involved is shown in prior Patent No. 1,514,210, issued to Walter A. Heinrich, November 4, 1924.

Among the several objects of the present invention may be noted the'provision of a fuse cartridge, including means for mounting a fuse therein, so that said fuse will not be under mechanical stress during normal opert ation but which, upon a blowing action of the fuse, is immediately put under a stretching stress, whereby the resultin gap in the fuse (due to blowing) is immediately elongated, with t-he result that the fusing arc is more quickly broken and the line unloaded; the provision of a device of the class described-'adapted to prevent escapevot` gases into the box in which it is mounted; and the provision ofl a fuse of the class described which is rugged but .economical of construction and positive in operation. lOther objects will be in part obvious and in part pointed 3 hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangements ofparts, which are exemplified inthe description hereinafter in connection with the accompanying drawings, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is o illustrated one of various possible embodiments of the invention, f

Fig. 1 is a partial vertical section ofthe ,box into which the fuse fits, showing certain Y parts in" full; y.

Fig.,2 is a longitudinal section of the cartridge showing the vfuse mounted therein in unstressed position; v

Fig.3 is an enlarged section of the head of the cartridge taken at 90 degrees to the Fig. 2 section, that is, on line 3-3 of Fig. 1; and

1927. Serial No. 183,65?.

1, there is illustrated at numeral 1 a line box having bolted therein spaced insulator members 3, the latter supporting spaced line engaging elements or clips 5, respectively connected to the line wires. The fuse cartridge, to be described, is adapted to be resilient-ly held within the spring clips 5 and socketed in a hinging member 9, the latter extending from a lower opening 11 in the box 1.

The cartridgey proper comprises two, preterably fibre insulating tubes 13, 15, held together by a lower band 17, and a central metallic band and terminal piece 19. At its upper end, the longer of the two tubes (tube 15) is provided with another metallic termiynal assembly A, which includes the stressing construction to be described.

The terminal piece or engaging element 19 and thee/terminal assembly or second terminal engaging element A are adapted to be put into an electrical connection by means of a fuse wire 21. The lower end of the wire lwhich is positioned in the shorter tube 13, is.

connected to said terminal piece or engaging element 19 by means of an anvil and set screw combination 23, whereby it is put into electrical connection when the terminal 19 is positioned in the lower spring clips 5. The fuse wire -2 1 passes downwardly out of the short insulating tube 13 and up into the long insulating tube 15.

The head of the tube 15 is *fastened to a terminal piece 25 adapted to be engaged by said upper spring clip 5. This terminal piece 25 is bored out to slidably receive a movable -fuse support 27 which is positively putinto electrical connection. with the terminal piece 25 by means of a length of flexible wire 29. The members 25 and'27 are also -in electrical connection at their sliding joint but the wire 29 makes the connection between the two more positive.

A compresslon spring or strained element 31 is positioned to react between the slidable p spring 31 (see Fig. 3). The key 37 is then held in position by the shearing tendency' of the member 27. The inner end of the key 37 has a substantial area exposed to the hollow space within the fuse.

The upper end of the member 27 is also provided with a set screw and anvil combination 39, similar to the said combination 23, whereby the other end ofthe fuse wire 21 may be fastened into the cartridge, said cartridge being then in its Ashortened position shown in Fig. 3.

The operation of the cartridge, assuming that the terminal engaging elements 19 and 25 are in position within the terminal clips 5 of the line, is as follows:

The spring 31 tends to press thefuse holding or supporting member 27 upwardly but the key 37, being inI an obstructing position prevents this action. The key 37 is itself maintained in position by the pressure of the member 27 Thefuse 21 is long enough that under the above described conditions it may be positioned'in the anvil combinations 39 without an elongating mechanical stress and consequent strain being engendered.

In the above manner the clips 5 are put into electrical connection and the line circuit is closed. The line circuit may be opened without the fuse blowing by pulling the fuse tothe let (Fig. 1) on its hi-nging piece 9 and removing it from said last-named piece. A bridge 10 is provided for applying a tool to the cartridge for purposes of removal.

However, if the lcartridge is in position across thel terminals 5 and an electric overload comes on, the fuse will blow at its most restricted area 41. The blowing action is somewhat explosive and results in an internal pressure being built up within the tube 15 and elements connected therewith. This causes the V`key 37 to be pushed outwardly thereby releasing all obstructions to the upward movement o f the member 27, the latter being under action of the s ring 31 and the expulsive and recoil'action o the gases ejected from the'opening at the lower ends of the tubes 13, 15. Thus the resulting are is quickly broken and the line unloaded, more quickly than when no relative movement of the fuse ends is had. y Y.' The skirt 43 of the supporting'member 27 is long enough to provide a seal over the recess 35 as the fuse' blows.

This fuse has an advantage over thosethat are maintained under const-ant tension, namely, tliat-when a heavy load comes on, which merelysoftens the fuse but `is not enough to require blowing, this present fuse4 does not tend to stretch and cause an unnecessary break. In fuses of the constanttension type, an incipient softening results in an unnecessary breaking by stretching, before the I electrical load reaches t-he value desired for blowing the fuse.

After each blowing of the present fuse, it

may be readily'reset by pressing the member invention, it is intended that the above description and accompanying drawings and claims shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A fuse cartridge comprising spaced terminal engaging elements, a fuse held in electrical connection with said engaging elements, a compression spring tending to increase the distance between points of connection-of said fuse with the terminal engaging elements, andv means for resisting said tendency, the explosive pressure occasioned by. the rupture of said fuse being adapted to prevent the resisting operation of said resisting means.

2. A fuse cartridge comprising spaced terminal engaging elements, a fuse held in electrical connection with said engaging elements, a compression spring tending to increase the distance between points of connection of said fuse with the terminal en agin elements, and means for resisting sai ten ency, the explosive pressure occasioned by the rupture of said fuse being adapted to prevent the resisting operationof saidresisting means, said compression spring carrying at least some. current which passes through the fuse.

3. In a fusecartridge, terminal engaging elements, tubular means joining said elements and carrying a fuse link therein having electrical connections with said elements, strained'.

means tending to increase the distance between the points of connection ot the fuse with the engaging elements, said strained means being located externally of said tubular means, and means for resisting the tendency to increase said distance, the explosive lar portion having an opening therein, the

fuse link having electrical connections with said elements, strained means tending to increase the distance between the points of cony nection of the fuse with the engaging elements, said strained means being located ex-A ternally of said tubular means, and means for resisting the tendency to increase said distance, the explosive pressure occasioned by the rupture of said fuse being adapted to actuate said resisting means to release said distance-increasing means for operation, the distance-increasing means being effected at least by eirpulsive action fromsaid opening. whereby the resulting arc is broken.

In testimony whereof, I have signed my name to this specification this 12th day of April, 1927.

LESTER P. BOLL.

in part by reaction due to expulsion of gases from said opening.

5. In a fuse cartridge, spaced terminal engaging elements, a fuse electrically connected near its respective ends of said elements and having a bent portion between the points of security, a tubular member enclosing said fuse from element to element and provided with an opening to receive the bent portion of the fuse,'a movable member for securing one end of the fuse to one terminal engagin element and means causing movement of sai movable menibe upon rupture of the fuse -to separate the ends of the'fuse link, due at least in part to reaction due to expulsion of gases from said opening.

6. In a fuse cartridge, spaced terminal engaging elements, a fuse electrically connected near its respective ends of said elements and having a bent portion between the points of security, a tubular member enclosing said fuse from element to element and provided with an opening to receive the bent portionof the fuse, a movable member for securing one end of the fuse to one terminal engagin element and means causing movement of sai movable member upon rupture of the fuse to separateythe ends of the fuse link, due at least in part to reaction d@ to expulsion oigases from said opening and means adapted to resist movement of rupture operable by a rise in pressure upon rupture of said fuse to permit movement.

7. In a fuse cartridge, spaced terminal engaging elements, a tubular portion leading from one of said engaging elements, a. fuse link electrically joining the elements and passing through said tubular portion, the tubular portion having an opening at the end opposite one of the engaging elements, a mov-` able member in saidenga'ging element at said last-named end for supporting one end of the fuse adapted to be moved upon rupture of said fuse, due to rise in pressureA caused 

